dance bio 5

In garden peas, a single gene controls stem length. The recessive allele (t) produces short stems when homozygous. The dominant allele (T) produces long stems. A short-stemmed plant is crossed with a heterozygous long-stemmed plant. Which of the following represents the expected phenotypes of the offspring and the ratio in which they will occur?

1 long-stemmed plant: 1 short-stemmed plant

A couple has 5 children, all sons. If the woman gives birth to a sixth child, what is the probability that the sixth child will be a son?

1/2

A researcher is crossing two organisms that are heterozygous for three Mendelian, unlinked traits (XxYyZzXxYyZz). Which of the following is the fraction of offspring that are predicted to have the genotype xxyyzzxxyyzz?

1/64

If 2n = 48 for a particular cell, then the chromosome number in each cell after meiosis would be

24

For the following group of questions first, study the description of the situation and diagram and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet. The pedigree of a family with a history of a particular genetic disease is shown below. Squares represent males and circles represent females. Shaded symbols represent those who have the disease Individual 6 marries a woman with the disease, what is the probability that their first child will have the disease?

50%

In the following human pedigree, squares represent males, circles represent females, and shaded symbols indicate individuals affected with a disorder. One of the affected males from the third generation has a child with a female who is a carrier. For the pedigree shown above, which of the following best expresses the probability that the couple's first son will be affected with the disorder?

50%

Which of the following critical values should the scientist use for the chi-square analysis of the data?

7.81

For following group of questions first study the description of the situation and diagram and then choose the one best answer to each question following it and fill in the corresponding oval on the answer sheet. The pedigree of a family with a history of a particular genetic disease is shown below. Squares represent males and circles represent females. Shaded symbols represent those who have the disease.

Autosomal recessive

Tay-Sachs disease is a rare inherited disorder caused by an autosomal recessive allele of the HEXA gene. Affected individuals exhibit severe neurological symptoms and do not survive to reproductive age. Individuals who inherit one copy of the allele (Tay-Sachs carriers) typically show no symptoms of the disorder. The frequencies of Tay-Sachs carriers in the general population of North America and in three different subpopulations are presented in the table. Which of the following pedigrees most accurately represents a family with a history of Tay-Sachs disease?

B two dots

Butterflies of the genus Colias live in the Rocky Mountains, where they experience a wide range of temperatures. Different variants of a particular glycolytic enzyme in the flight muscles are optimally active at different temperatures. Within the same population, some individual butterflies fly most effectively at 29°C , while others fly most effectively at 40°C. Still others can be equally active at both temperatures. Which of the following claims is most consistent with the observed butterfly behavior?

Butterflies that express

Directions: This group of questions consists of five lettered headings followed by a list of phrases or sentences. For each phrase or sentence, select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. This group of questions refers to the probabilities below. Assume that the alleles referred to all assort independently. (A) 0 (B) 1/16 (C) 1/4 (D) 1/2 (E) 3/4

CD 1/16

The process depicted in the image above is best summarized by which of the following descriptions?

During meiosis

In the spring and summer, the fur of an arctic fox contains a pigment called melanin that gives the fox's fur a dark color. In the fall and winter, the fur of the arctic fox is white. Which of the following most likely explains how the changing seasons result in changing fur color in an arctic fox?

Envoirmental factors cause changes

Which of the following best supports the claim that organisms of different domains share a common ancestor?

Glycolysis

Figure 1. Pedigree of an inherited trait Based on the pedigree in Figure 1, which of the following best explains the observed pattern of inheritance?

I-2

Which of the following is the correct sequence of these events?I. Synapsis occurs.II. Crossing-over is completed.III. Condensation of chromosomes begins.IV. Separation of homologous chromosomes begins.

III,I

All of the following are true statements about meiosis in mammals EXCEPT:

It produces four genetically identical gametes.

A spermatocyte produces the following four sperm cells. These cells are the result of nondisjunction during which of the following phases?

Meiosis I

Gregor Mendel's pioneering genetic experiments with pea plants occurred before the discovery of the structure and function of chromosomes. Which of the following observations about inheritance in pea plants could be explained only after the discovery that genes may be linked on a chromosome?

Most offspring

Which of the following best describes the most likely effect of the formation of a triplex DNADNAstructure (Figure 3) on the synthesis of the frataxin protein?

RNA polymerase

Which of the following represents a cross between a white-eyed female and a red-eyed male?

Rr

irections: This group of questions consists of five lettered headings followed by a list of phrases or sentences. For each phrase or sentence, select the one heading to which it is most closely related. Each heading may be used once, more than once, or not at all. This group of questions refers to the probabilities below. Assume that the alleles referred to all assort independently. (A) 0 (B) 1/16 (C) 1/4 (D) 1/2 (E) 3/4

TS 1/4

Which of the following best describes the hydrolysis of carbohydrates?

The addition of a water molecule breaks

The data above represent the results of three different crosses involving the inheritance of a gene that determines whether a certain organism is blue or white. Which of the following best explains the mechanism of inheritance of the gene?

The allele for blue is an X-linked dominant

Which of the following occurs during mitosis but not during meiosis I ?

The chromatids

Which of the following statements best predicts the consequence if meiosis did not occur during gametogenesis?

The chromosome number would double

The three-spined stickleback (Gasterosteus aculeatus) is a small fish found in both marine and freshwater environments. Marine stickleback populations consist mainly of individuals with armor-like plates covering most of their body surface (completely plated). Approximately 10,000 years ago, some marine sticklebacks colonized freshwater environments. After many generations in the freshwater environments, the freshwater stickleback populations lacked completely-plated stickleback from a marine population was mated to a low-plated stickleback from a freshwater population. The resulting F1 hybrids all displayed a completely plated phenotype. When the F1 hybrids were allowed to interbreed, the resulting F2 generation included completely plated offspring and low-plated offspring in an approximate 3:1 ratio. Which of the following conclusions is best supported by the results of the breeding experiments?

The completely-plated

Which of the following provides the best justification for an assumption that might have been used in the computer simulation (Table II)?

The purple allele is dominant

In humans, red-green color blindness is a sex-linked recessive trait. If a man and a woman produce a color-blind son, which of the following must be true?

The mother carries the allele for color blindness

Which of the following best explains why triploid bananas do not produce seeds?

The production of gametes

A series of crosses is performed with fruit flies (Drosophila melanogaster) to examine inheritance of the genes vestigial (vg) and cinnabar (cn). The recessive vg allele causes small, malformed wings called vestigial wings. The recessive cn allele causes bright-red eyes called cinnabar eyes. In the first cross, a female with wild-type wings and eyes is mated with a male with vestigial wings and cinnabar eyes. All the F1 individuals have wild-type wings and eyes. In the second cross, female F1 flies are mated with males with vestigial wings and cinnabar eyes. The phenotypes of 500 F2 individuals are shown in the table Which of the following is the most likely explanation of the results?

The two genes are linked on an autosome.

Which of the following best describes the cells that result from the process of meiosis in mammals?

They are genetically different

In peas the trait for tall plants is dominant (T) and the trait for short plants is recessive (t). The trait for yellow seed color is dominant (Y) and the trait for green seed color is recessive (y). A cross between two plants results in 296 tall yellow plants and 104 tall green plants. Which of the following are most likely to be the genotypes of the parents?

TtYy x TT

Some green sea turtle females deposit their eggs in nests that are dug on warm, tropical beaches. Researchers have studied the effects of temperature on the hatching rate and the proportion of female to male hatchlings produced at different average nest temperatures in Suriname (Figure 1). At temperatures below 23°C23°Cor above 33°C33°C, the eggs do not develop. Which of the following best describes the results shown in Figure 1 ?

Warmer nests

Based on the data in Figure 1, which of the following best describes the inheritance pattern of Friedreich's ataxia?

autosomal recessive

The pedigree below shows the inheritance of a dominant allele of a gene in a family over several generations. Circles represent females and squares represent males. Shaded symbols indicate individuals carrying the allele. The pedigree suggests that the gene is on a nuclear chromosome, and not on mitochondrial because

maternal mitochondrial

A culture of white-eyed fruit flies (Drosophila melanogaster) was maintained for many generations. Females from the stock white-eyed culture were crossed with red-eyed (wild-type) males. The F1 females were crossed with the white-eyed males from the original culture. The resulting phenotypes of the progeny are summarized below. Which of the following best describes the mode of inheritance of eye color in the white culture?

sex-linked

In the F2 generation, the results are best explained by the fact that

these genes for eye color and wing shape are found on the same chromosome

Within a forest ecosystem, there is a large amount of diversity among members of a warbler species. Of the following stages of meiosis illustrated for a typical cell, which contributes most to diversity among the warblers?

together